Thermoelectric Generators—An Enduring Technology

Wherever there is a difference in temperature, it is possible to generate electricity with no moving parts from a junction of two different materials. Not only can campers recharge their mobile phones from a camp stove, Voyager 1, the most distant spacecraft launched from Earth, has been powered for more than 44 years by the heat from decay of lumps of plutonium-238 in thermoelectric generators.